This bottle opener is made out of 14 gauge hot-rolled mild steel covered with a thin layer of black oxide (magnetite) which is responsible for its dark gray/bluish tint. While this provides a level of protection against corrosion, a beautiful patina of rust can be brought out by minimal amount of exposure to humidity. If the rust is unwelcome you may rub a grade 3 coarse steel wool over the top to remove any and/or all rust.